The use of electronic personal directories allows the storage of a specific network address on any number of communication devices unrelated to the specific network address. This storage may be used to quickly transmit a message and/or contact an individual associated with the specific network address, and as a way of managing contacts/relationships. Under certain conditions it may be useful to know who has potentially been in contact with the specific network address. For example, in the case of pandemics, terrorism prevention and/or crime investigations, it may be important to determine who has potentially been in contact with an individual associated with the specific network address. Less dramatically, in a company it may be useful to determine who has potentially been in contact with an individual associated with the specific network address in order to prevent redundant contact with the individual, for example a client or potential client.
In some instances, telephone records and/or call history (where available) can be used to identify who has been in contact with the specific network address. However, this only identifies established calls involving the telephone number, and is further limited to the telephone system where the records are collected.